1. Field of the Invention
The present invention relates generally to electronic circuit packaging and manufacture and, more particularly, to a method an and apparatus for electrically and mechanically connecting an electronic circuit to a card using a solder ball bonding technique.
2. Prior Art
U.S. Pat. No. 4,657,169 teaches a technique for non-contact detection of liquification of solder in a reflow soldering operation by examining the rate of change of the solder temperature or by detecting a change in a surface reflectance characteristic of the solder which occurs upon melting. Although the patent generally relates to electrical bonding of circuit elements through a soldering reflow operation, the patent does not teach or suggest the invention as taught and claimed herein.
German Patent 4000945 teaches measurement of temperature or temperature variation at soldered joints by detecting physical change such as the mechanical strength of the part changing from solid to liquid. Although the patent relates generally to soldered connections, the patent does not teach or suggest the present invention as taught and claimed herein.
U.S. Pat. No. 5,240,165 teaches a method of producing bonds of a lead to a bump on a semiconductor chip by controlling the amount of deformation of the lead in the bump during bonding. A differential amplifier is used to sense the deformation and stop the application of force to the lead in the bump when a desired amount of deformation of the lead in the bump is obtained. Although the patent teaches a method of bonding a lead to a bump on a semiconductor chip wherein deformation of the bump is sensed by a differential amplifier, the patent does not teach the improved bonding apparatus and method according to the present invention as taught and claimed herein.
U.S. Pat. No. 5,317,125 teaches a method and apparatus for monitoring the temperature of a work piece during fusing operations. The patent teaches a different measurement technique than is included in the present invention as taught and claimed herein.
U.S. Pat. No. 5,386,092 teaches a fast response weld head which employs a control system to allow user control of critical welding parameters such as speed, force, position, and duration. The patent teaches a control system using a force measurement to measure the force exerted by the electrode on the work piece to control a welding operation. The patent does not teach or suggest the present invention as taught and claimed herein wherein force is not measured.